Here's how you can help victims of the El Paso shooting

EL PASO, Texas – Reports of 20 killed and more injured in a mass shooting at an El Paso Walmart on Saturday have sparked a call for blood and monetary donations.

Roger Ruiz, a spokesman for the South Texas Blood and Tissue Center, said that the blood supply remains low in San Antonio.

He said that blood shortages are most critical during the summer, adding: "We’ve taken extra measures this summer to ask everyone who can to donate to meet needs of patients every day and because its critical to have blood on the shelves before tragedies like this happen. It’s a sobering reminder that its critical to have adequate blood supplies on the shelves at all times, before tragedy strikes. This is true in accident victims but also for cancer patients."

Ruiz said the South Texas Blood & Tissue Center is also in need of platlets.

The American Red Cross said it will help El Pasoans during this time. The nonprofit issued the following statement:

"We have deployed Red Cross volunteers from the Greater San Antonio chapter to assist our West Texas neighbors with emotional and mental health services for the victim, families of victims and the community of El Paso."

Ruiz said locally, few people have signed up to donate blood in the coming days.

Those interested in donating can do so Sunday at the following locations: